The trailer also talks about taking on a rite of passage called "The Island Challenge", and it really looks like something that might replace the old gym system. Instead of gym leaders, you've got "trial captains", which will issue different sorts of challenges to the player.

If successful, the player can encounter something called "totem Pokemon" at the end of each trial, and these appear to be special, souped-up versions of already existing Pokemon. Additionally, these new monsters can call for help in the middle of battle, causing more Pokemon to appear.

In addition to trial captains, there are also "Kahunas", which the player can take on after winning trials:

Finally (phew!), Sun and Moon will introduce "Z-moves", which can be used only once per battle but look downright devastating:

Every type in the compendium will have its own special Z-Move, all of which are triggered by trainer dance moves. Awesome.

Coming to the next Pokémon game... you can just forget everything about what you thought you knew about Pokémon because we're scrapping it all and no Pokémon is safe! That electric one you love. Nope! It's now a normal type! OMG, such innovate.

Colour?! Fuck that! We just picking every colour and no throwing it over every Pokémon. Now everyone can have every colour! Every Pokémon is a shiny!

Glad to see Nintendo & Game Freak really mixing things up for the game. New forms for traditional Pokemon is a neat ideal, especially as how some of them get new types too (such as Exeggutor getting a dragon type but losing its psychic type).